There is a related art in which a transmitting side communication apparatus receives, from a receiving side apparatus, notification of a frame format decided in accordance with a frame reception status or the like, and changes the frame format.
However, in the related art, even when a broad band (e.g., a millimeter waveband of 30 GHz to 300 GHz) is used, a time required for automatic gain control (AGC), which is processing performed by an analog circuit, cannot be sufficiently reduced as compared with a communication time of a data portion.
When a field for automatic gain control is too long, an increase in overhead (time required for automatic gain control) is provoked, and when the field for automatic gain control is too short, automatic gain control cannot be sufficiently carried out at the receiving side apparatus, resulting in degradation in reception performance.